The present invention relates generally to an electronic test station for testing electronic devices and, more particularly, to test adapters for configuring the electrical communication between a unit under test and an electronic test station.
Complex electronic systems are commonly employed in an increasing number of applications, such as onboard commercial and military aircraft. These complex electronic systems are typically comprised of a number of smaller electronic units that are electronically connected. The configuration of these units creates an overall system that can be tested and maintained by looking at the system on a unit by unit basis. Thus, the entire electronic system need not be scrapped due to the failure of a component or a unit. Instead the unit that has failed can be individually identified and replaced.
As such, industries using complex electronic systems often employ test stations with test adapters to test these units, typically referred to as units under test (UUTs). For example, one commonly used test station, the ATS-182a model automated test station, is designed to test various UUTs in the avionics industry. Test stations generally provide a UUT with a number of electrical signals and measure the corresponding responses. Based upon these responses, the test station can troubleshoot the UUT. In order to communicate with the UUT, a test station typically includes an interface panel that is connected to the UUT by means of a test adapter. For example, the ATS-182a test station has a patchpanel interface provided by AMP Incorporated that employs leaf spring paddles for receiving respective pins of the test adapter. In this regard, after the UUT is connected to the test adapter, the test adapter is connected to the ATS-182a test station by securing the test adapter to a holding frame that aligns the pins with the leaf spring paddles. By actuating a lever arm, the pins are forced against the leaf spring paddles.
While one test station can be used to test various UUTs, the varying nature of these UUTs oftentimes requires test adapters to be customized for the UUTs to ensure that a specific type of UUT can communicate with the test station. Typically, test adapters are customized by technicians who hand wire the test adapters to permit as many as 1,768 unique connections between the test station and adapter alone. Hand wiring each adapter can be very labor intensive, error prone and costly to implement. Facing this problem, a number of alternative test adapters have been developed. For example, U.S. Pat. No. 4,922,191 issued May 1, 1990 to Conover (hereinafter xe2x80x9cthe ""191 patentxe2x80x9d) discloses an interconnection assembly for connecting a UUT to a test station, including a testing unit and an interface test adapter unit having signal relaying circuitry for electronically interfacing between the testing unit and a UUT. While test adapters such as that of the ""191 patent eliminate the need for hand wiring each adapter, they require uniquely designed test stations, and are generally not compatible with existing, commonly used test stations.
Another type of test adapter design, disclosed in U.S. Pat. No. 5,793,218 issued Aug. 11, 1998 to Oster et al. (hereinafter xe2x80x9cthe ""218 patentxe2x80x9d), includes an interface frame and an interchangeable circuit card assembly configured to route signals between the test station and UUT. The ""218 patent further discloses the test adapter connected to the test station either by means of a ribbon cable assembly, a connector block with wires connecting to contact pins, or a connector strip on the adapter itself. While the design of the ""218 patent also reduces the need for hand wiring each adapter, the interface between the adapter and test station presents additional drawbacks. The connection means between the adapter and test station does not lend itself to easy adoption into current, commonly used test stations. Additionally, connecting the test adapter to the test station by means of a ribbon cable assembly or connector block with wires adds complexity to the test adapter design and makes operation of the test adapter more cumbersome.
In view of the foregoing background, the present invention therefore provides an improved test adapter and an associated separator plate for configuring the electrical communication between a UUT and an electronic test station, particularly existing, commonly used test stations, without requiring that the test adapter be hand wired. The test adapter of the present invention comprises a printed wiring board having two major opposed surfaces, and consisting of at least one electrically conductive path and at least one connection terminal in electrical communication with the electrically conductive path, whereby the connection terminal connects the UUT to the adapter. In one embodiment, the printed wiring board further includes at least one electrical protection network in electrical communication with the electrically conductive path. The test adapter of the present invention also,includes a plurality of electrically conductive pins that are in electrical communication with the conductive path and extend outward from a first surface of the printed wiring board, wherein the pins are adapted to electrically connect the test adapter to the test station. To space the printed wiring board from the electronic test station so as to eliminate mechanical interference between them, the test adapter of the present invention also includes a separator plate, made from an insulative material such as an epoxy glass, situated adjacent to the first surface of the printed wiring board, wherein at least a portion of the separator plate includes a plurality of apertures through which the pins extend.
In one embodiment, the test adapter further includes an insulative connecting member having two major opposed surfaces and at least one connector adapted to attach the connecting member to the test station. At least a portion of the connecting member further includes a plurality of openings such that when the connecting member is secured to the separator plate, the pins extend through the openings. Additionally, the connecting member can include a frame that extends peripherally about the connecting member, including that portion of the connecting member that defines the openings, and that includes the connector.
In another embodiment, the test adapter further includes an enclosure mounted to the printed wiring board such that the electrically conductive path of the printed wiring board is within the enclosure. The enclosure can also be mounted to the printed wiring board such that the terminal of the printed wiring board is outside the cavity. In one embodiment, the test adapter includes further at least one daughter printed wiring board having at least one electrically conductive path that is mounted to a side wall of the enclosure and is connected to the printed wiring board such that the electrically conductive path of the daughter printed wiring board and the electrically conductive path of the printed wiring board are in electrical communication.
According to one aspect of the present invention, the separator plate includes first and second opposing surfaces. In this embodiment, the second surface of the separator plate includes a frame extending peripherally thereabout and outward therefrom such that the frame defines a recessed medial portion of the second surface. Also in this embodiment, the separator plate has a plurality of apertures, typically situated in a rectangular array, opening through the recessed medial portion of the second surface for providing access for the pins extending between the test adapter and the test station.
In one embodiment, at least a portion of the printed wiring board includes a plurality of contacts in electrical communication with the electrically conductive path. In this embodiment, the test adapter further includes a plurality of electrically conductive sockets disposed in mechanical and electrical communication with respective ones of the contacts such that the sockets and the electrically conductive path are in electrical communication. The pins are then disposed at least partially within the sockets and extend outward therefrom such that the pins and the sockets are in electrical communication.
Each pin preferably has first and second opposing segments. The first segment has a diameter smaller than the openings in the connecting member, but the second segment has a diameter larger than the openings. Due to this diameter difference between the first and second segments, when the second segment is disposed within the sockets and the connecting member is secured to the separator plate, the first segment, but not the second segment, will extend through the connecting member.
The test adapter of the present invention therefore offers an improved test adapter for configuring the electrical communication between a UUT and an electronic test station, particularly existing, commonly used test stations. By employing a printed wiring board, the test adapter eliminates the need for hard wiring the test adapter for use with varying UUTs. Also, the pin arrangement on the test adapter provides a compatible interface with existing, commonly used test stations. Moreover, the pin and separator plate arrangement makes the test adapter design capable of being directly interfaced with the test station without requiring added wire or ribbon cable assemblies that can add complexity to the test station and test adapter arrangement.